Under this grant we propose to develop and apply a new class of fluorescent oligonucleotide probes based on a novel high performance lanthanide complex. By virtue of their long fluorescence emission lifetimes, lanthanide reporter oligonucleotide probes will offer fundamentally improved performance over conventional fluorescent probes. The lanthanide chelate complex is a new design based on a quartet of amine substituted isopthalamide ligands. Lanthanide complexes prepared from this chelate are stable while they capture and emit light more efficiently than previous designs, potentially allowing assays with greater S/N, and thus greater sensitivity. Our Phase 2 primary objectives will focus on the development of "quenched" oligonucleotide probes based on the lanthanide complex, and their application to a variety of genetic assay types, both for "real time" and end point analysis. We will seek to take advantage of the long fluorescence lifetimes of lanthanide reporters by employing "gated" detection of lanthanide fluorescence under thermocycling conditions for PCR assays. [unreadable] [unreadable]